Although adolescents up to the age of 21 are considered by the National Cancer Institute to be under the purview of the pediatric cancer cooperative groups, those aged 15 to 21 are grossly under-registered in these groups, compared to nearly universal registration of younger cancer patients. This disparity deprives adolescents of the survival advantage shown to benefit pediatric participants in clinical trials and it prevents the academic community from systematically making advances in therapy. There is mounting evidence that "best practice" for adolescents with most cancers is management by a pediatric oncologist at a tertiary care center with access to all that entails, including registration with a pediatric cancer cooperative group and availability of clinical trials. Adolescents are not being registered with the pediatric cooperative groups and are not being treated on clinical protocols because they are not being referred to pediatric oncologists. We propose to examine, by surveying primary care physicians, the factors influencing the referral of an adolescent with cancer. We will analyze responses to hypothetical case vignettes and will interview physicians who report having recently diagnosed an adolescent with cancer. We hope to determine physician characteristics (including specialty) or patient characteristics that can predict the referral pattern for older pediatric cancer patients. We hope to elucidate whether the behavior of the referring physician is a barrier in the access to appropriate care. Determining these factors and beliefs is critical to understanding the discrepancy in care between younger children and adolescents with cancer.